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ABSTRACT

AR1-SO2-N(-Z)-SO2-AR2-A-Y-A-AR3(-A-Y-A)-SO2-N(-Z)-SO2-R   DYED WITH BASIC DYESTUFFS COMPRISING A CONVENTIONAL HIGH MOLECULAR WEIGHT AROMATIC FIBER FORMING POLYAMIDE, CONTAINING REPEATING CARBONAMIDE GROUPS AS AN INTEGRAL PART OF THE POLYMERIC CHAIN SEPARATED BY A MEMBER SELECTED FROM THE GROUP CONSISTING OF AROMATIC AND AROMATIC HETEROCYCLIC MOIETIES AND FROM 3 TO 30 PERCENT BY WEIGHT, BASED ON THE COMPOSITION AS A WHOLE OF A POLYAMIDE WHICH COMPRISES FROM 30 TO 100 MOL. PERCENT OF DISULFONEIMIDE SEGMENTS OF THE FORMULA: WHEREIN EACH SYMBOL A REPRESENTS A GROUP OF THE FORMULA -CONH- OR -NHCO-, Z REPRESENTS A HYDROGEN OR ALKALI METAL ATOM, R REPRESENTS A C1 TO C4 ALKYL RADICAL OR AN AROMATIC, ALKYL-SUBSTITUTED AROMATIC OR HALOGEN-SUBSTITUTED AROMATIC RADICAL, AR**1 AND AR**2, WHICH CAN BE THE SAME OR DIFFERENT, EACH REPRESENTS A BIVALENT AROMATIC, ALKYL-SUBSTITUTED AROMATIC OR HALOGENDISUBSTITUTED AROMATIC RADICAL, AR**3 REPRESENTS A TRIVALENT AROMATIC, ALKYL-SUBSTITUTED AROMATIC OR HALOGEN-SUBSTITUTED AROMATIC RADICAL, AND Y REPRESENTS A DIVALENT AROMATIC RADICAL AND FROM 0 TO 70 MOL PERCENT OF SAID CONVENTIONAL AROMATIC POLYAMIDE SEGMENTS.

XR RE 28!.314

United States Patent Uthce SEARCH ROOI'W Reissued Jan. 21. i975 Matt -nclosed in heavy brackets If] appears In the oriflnal patent but forms no part of this reissue specification: matter printed in italics lndleates the additions made by reinc- ABS'IRACT OF THE DISCLOSURE A polyamide composition of matter that can be dyed with basic dyestuifs comprising a conventional high molecular weight aromatic polyarnide and 3 to 30 percent by weight of an aromatic polyamide containing 30-100 mol percent of removing structural units with disulfone imide structures.

This invention relates to high molecular weight aromatic polyamides that can be dyed with basic dyes and contain a proportion of amide units with disulphimide structures.

As a rule. polyamides obtained. by interfacial polycondensatron or by polycondensation in solution. from Fully aromatic diamtnes or aromatic diamines containing heterocycles and aromatic dicarboxylic acid dihalides, do not show any aflinity for basic dyes. In order to be able to dye aromatic polyamides with basic dyes. the necessary affinity for these dyes must be imparted to them by introducing acid groups. Thus. it is known that the dye absorption of aromatic polyamides can be improved by the addition of co-condcnsable carboxylic acid derivatives (US. Pat. No. 3,380,696) or of co-condensable sulphonic acid derivatives (published Netherlands Pat. application No. 6717240) or even of co-condensable compounds containing disulphimide structures (German Pat. application No. P 20 00 927.2).

The fully aromatic polyamides or the aromatic heterocycle-containing polyamides are polymers that are unafiected by high temperatures. and must meet stringent requirements in regard to tensile strength and thermal stability. It diamines containing acid groups. for example. are co-condensed ill a concentration of from 5 to mol percent {based on the total quantity of diamine). every tenth to twentieth diamine unit statistically distributed through the polyamtde chain is derived from a diamtne with an acid group. Although the dyeability of such copolyamides is greatly increased. their strength and thermal stability are impaired.

The present invention is based on the discovery that the -utsiauding properties of the polyamides show very little deterioration when the fundamental structure of the fully aromatic or aromatic heterocycle-contalning homopolyamides is left intact. and instead as little as possible of a polyamide or copolyamide highly enriched with disulphimide groups is added to the polyamides in order to improve their atfinity to dyes.

It is an ob ect of this invention. therefore, to provide a polyamide composition of matter that can easily be dyed with basic dvestutfs. and the physical properties of which are not deteriorated. Further objects or the invention will be evident from the description and the exam ples. These objects are accomplished by a polyamide composition of matter that can be dyed with basic dyestulfs comprising a conventional high molecular weight aromatic polyamide and from 3 to 30 percent by weight. based on the composition as a whole of a polyamide which comprises from 30 to l00 moi percent of disulfoneimide segments of the formula:

wherein each symbol A represents a group of the formula CONI1 or --NHCO-.

Z represents a hydrogen or alkali metal atom.

R represents a C to C. alkyl radical or an aromatic, alkyl-substltuted aromatic or halogen-substituted aromatic radical.

Ar and Ar", which can be the same or different. each represents a bivalent aromatic. alkyl-substituted aromatic or halogen-substituted aromatic radical,

Ar represents a trivalent aromatic, alkyl-substituted are matic or halogen-substituted aromatic radical. and

Y represents a divalent aromatic radical and from 0 to mol percent of conventional aromatic polyamide seg ments.

.Ar and Ar in the above formula which can be the same or different, preferably each represents a bivalent arc matic radical consisting of one aromatic ring or of two or more aromatic rings which are fused together or are attached to one another through a direct bond or through a CH,, --O, -S- or SO radical.

Ar represents a trivalent aromatic radical, which can also consist of one aromatic ring or of two or more aro= rnatic rings which are fused together or are attached to one another through a direct bond or through a --O. -S-, or SO, group. or an alkyl or halogen-substituted aromatic radical.

In the context of the present invention conventional high molecular weight aromatic polyamides include. on the one band. fully aromatic polyamides and. on the other hand. polyamides which in addition to aromatic radicals also contain heterocyclic radicals in the chain, but not those which contain aliphatic radicals in the chain.

The structural segments of conventional aromatic polvamides are derived from the following aromatic did-HD1131 and aromatic dicarboxylic acids: Diamines:

mand p-phenylene diamine. 4,4'-Diaminodiphenylerher. 4.4'-diaminodiphenylsulfide. 4,4- and 4.3'-diaminoben zam'lide.

2,6- and ZJ-diaminonaphthalene, benzidine. l.3-bis-(p= amino-benzimido)-benzene. 1.4-bis-(m-aminobenzariti doJ-benzene.

3'.3"-diam1noterephthalic acid dianilide. 1'" 4"-diamino\so phthalic acid dianilide. ZJ-bislmand p-aminophenyl): 1.3.4-oxdiazole. 3,5-bis( m-am|nophenyl -4-phenyll,..4- triazole. 2.5 -bis-( p-arninophenyU-1.3.4-thiadiazole.

ETA-amrnoohenosthme. .'.T-dltlfl'llllOPllt'JOXlllUP-WlOX lde.

HaN

HaN

Dicarboxylic acids: Isoand terephthalic acid, 4,4- benzophenone dicarboxylic acid, 4,4'-diphenyldicarboxylic acid. 1,5- and 2,6-naphthalene dicarboxylic acid. 4.4' di phenylether dicarboxylic acid, 4,4 diphenylsuifone (li carboxylic acid, and the corresponding dicarboxyiic acids substituted by halogen or alkyl.

The polyamides containing disulphimide structures are prepared by the homopolycondensation or copolycondem sation of aromatic diamines or dicarboxylic acid dihalides containing disulphimide groups through interfactal polycondensation or through polycondensation in solution The aromatic disulphimides used can correspond to the general formula:

in which each X represents an NH group or a -COHal group, in which Hal represents a halogen atom, preferably chlorine or bromine,

Z represents a hydrogen or an alkali metal atom. and

Ar and Ar, which can be the same or different. each represents a bivolent aromatic radical consisting of one aromatic ring or of two or more aromatic rings which are fused together or are attached to one another through a direct bond or through a CH;--. O, S- or SO,- group, or an alkylor halogen-substituted aromatic radical.

Alternatively, the aromatic disulphimide can also cor respond to the following general formula;

X X M,- 01

NZ la:

in which X and Z are as defined above,

R represents a C, and C. alkyl radical or an optionallv alkylor halogen-substituted aromatic radical, while Ar represents a trivalent aromatic radical. which can also consist of one aromatic ring or of two or more aromatic rings which are fused together or are attached to one another through a direct bond or through a --CH;. O. -S, or --SO,- group. or an al kylor halogen-substituted aromatic radical, preferably corresponding to the following formulas:

WI l (me For example. the following disulphimides which correspond to the above formulas can be used:

4,4'-diamino-diphenyl disulphimide 3,3'-diamino-diphenyl disulphimide 3,4-diamino-diphenyl disulphimide 3,3'-diamino-4,4-dichlorodiphenyl disulphimide 4,4-diamino-3,3'-dichlorodiphenyl disulphimide 3,3'-diamino-4-chlorodiphenyl disulphimide diphenyl disulphirnide-4,4'-dicarboxylic acid dichloride diphenyl disulphimide-3.3'-dicarboxylic acid dichlorde diphenyl disulphimide 3,4'-dicarboxylic acid dichloride 4- p-aminophenoxy) -3 '-aminodiphenyl disulphimide S-aminophenyl-4'-aminonaphthyl-( l )-disulphimide 3,5-diaminodiphenyl disulphimide 3.5-diamino-5-chlorodiphenyl disulphimide 3,5-diaminophenyl methyl disulphimide diphenyl disulphimide-3,5-dicarboxylic acid dichloride phenylmethyl disulphimide-3,5-dicarboxylic acid dichloride 1.5 -diamino-naphthyl- 3 -phenyl disulphimide 1,4-diamino-naphthyl-(6)-phenyl disulphimide. or 1,S-diamino-naphthyl-(3)-methyl disulphimide.

The disulphimides described above can be obtained by reacting sulphonic acid chlorides with sulphonic acid amides in alkaline medium [Ben 75, 532 (1942)] or by reacting sulphonyl thionylamines with sulphonic acids (German Pat. specification No. 1,235,300).

The homopolyamides or copolyamides containing disulphimide groups, used as additives to the high molecular weight aromatic polyamides to obtain the polyamide composition of matter according to the invention are preferably obtained by polycondensation in solution, although they can also be prepared by interfacial condensation. In the preferred procedure, a diamine containing the disulphimide group is introduced into a polar organic solvent, either on its own or together with a heterocyclic-containing diamine (although the disulphimide diamine should be present in a quantity of at least 30 mol percent, based on the total quantity of diamine), followed by the gradual addition in portion of the aromatic dicarboxylic acid dihalide. It is also possible, however, initially to introduce a fully aromatic or an aromatic heterocycle-containing diamine into a polar organic solvent and then to add a disulphimide-containing dicarboxylic acid dihalide, either on its own or in admixture with other aromatic dicarboxylic acid dihalides, gradually and in portions. in this case, too, the disulphimide-containing dicarboxylic acid dihalide should be present in a quantity of at least 30 mol percent. based on the total quantity of the dicarboxylic acid dihalides.

It is in the interests of the invention that the copolyamides containing disulphimide structures should contain as many disulphimide groups as possible. Accordingly, it is necessary to use as high as possible a percentage component of a disulphimide diamine, based on the total quantity of diamine, or of a dicarboxylic acid dichloride containing the disulphimide group, based on the total quantity of dicarboxylic acid dichloride, but at least 30 mol percent.

Examples of suitable polar organic solvents include N,N-dialkyl carboxylic acid amides, for example N,N- dimethyl acetamide, and N-substituted lactams, for example N-methyl pyrrolidone. The major advantage of these solvents is that it is possible to operate in the absence of additional acid acceptors. In order to obtain reaction products with the highest possible molecular weight, it 18 best to use the diamine component and the dicarboxylic acid dihalide component in equivalent or substantially equivalent quantities. Condensation is carried out at temperatures of from 30' to C., and preferably at temperatures of from -l0 to +50 C. The reaction times can range from I to 30 hours. The solutions have a solids content of from 5 to 40 percent by weight and preferably from 10 to 25 percent by weight.

If the diarnines and dicarboxylic acid dihalides have such structures that, together, they form polyamides that are insoluble in polar organic solvents, up to 5 percent by weight (based on the quantity of solvent) of an alkali metal salt or alkaline earth metal salt, preferably LiCl or Cacl must be added as solution promoter before or during polycondensation in order to prevent the polyamide formed from being precipitated from the solution.

These novel polyamides containing disulphimide structures consist of 30 to I00 mol percent (based on the total quantity of the structural segments derived from the diamines or from the dicarboxylic acid dihalides) of structural segments containing a disulphimide group corresponding to the general formulas:

in which A1" and Ar, which can be the same or different, each represents a bivalent aromatic radical consisting of one aromatis ring or of two or more aromatic rings which are fused together or are attached to one another through a. direct bond or through a -CH 0-, 4- or SO,- group, or an alkylor halogen-substituted aromatic radical,

Ar represents a trivalent aromatic radical, which can also consist of one aromatic ring or of two or more aromatic rings which are fused together or are attached to one another through a direct bond or through a CH,--, --O, \S, or SO,- group, or an alkvl or halogen-substituted aromatic radical,

R represents a C to C alkyl radical or an optionally alkyl-substituted or halogen-substituted radical,

Y represents a divalent aromatic radical.

2 represents a hydrogen or an alkali metal atom, and

A represents an amide group of the formula CONH or --NHCO-,

and of up to 70 mol percent of structural segments of known fully aromatic or aromatic heterocycle-contatmng polyamides.

The homopolyamides and copolyamides are coloriess or substantially colorless and have high or less high molecular weights, depending upon the structure of the monomeric units. Polyamides with high molecular weights can be converted by known methods into shaped articles such as filaments. fibers or bristles. According to the invention, however, the main application intended for these polyamides i unaifected by whether the molecular weights are very high or low) is that they should be added to known fully arch matic or aromatic heterocycle-containing polyamides in proportions of from 3 to 30 percent by weight. and prefer= ably from 5 to 15 percent by weight, depending upon the disulphimide group content, in order to impart to them an affinity for basic dyes. Dyed textiles prepared from copolyamides of this kind are extremely fast to washing.

EXAMPLE 1 a. Preparation of the disulphimide compound Two hundred parts by weight of a 20 percent by weight sodium hydroxide solution were added to a suspension of 202 parts by weight of m-nitrobenzene sulphonamide in 1200 parts by weight of water. A solution of 242 parts by weight of m-nitrobenzene sulphochloride in 400 parts by weight of acetone and 210 parts by weight of a 20 percent by weight sodium hydroxide solution were simultaneously dded drone rue at room temperature at such a rate as to maintain .a pH value of from 10 to 11. After stirring for 2 hours at 50 C.. the reaction mixture was cooled and liltel-ed under suction. and the product was washed with sodium hydroxide and water. The residue is sodium di- (tn-nitrophenyl)-disulphimide (melting point 254' to 255 C.) from which sodium di(m-am.inophenyl)disulphinii'de melting at 285 to 287 C. is obtained by catalytic hydrogenation.

b. Preparation of the polyamide spinning solution Solution I: 134 Parts by weight of 3-(p-aminophenyl)- amino-( lI-I,3H) quinazolin-2.4-dione were introduced into 950 parts by weight of absolute N-methyl pyrrolidone. ll.5 Parts by weight of isophthaloyl dichloride were then added in portions with continuous stirring at to l0 C. and the resulting highly viscous solution was stirred for another 12 hours at room temperature.

Solution II'. In the meantime, a solution of a copolycondensate was similarly prepared from 10.7 parts by weight of 3-(p-aminopheriyl)-7-amino-( [H.3Hl-quinazolin-2,4-dione, 13.5 parts by weight of sodium di-(m-aminw phenyll-disulphimide and 16.2 parts by weight of isophthaloyl dichloride in I22 parts by weight of absolute N- rnethyl pyrrolidone. Solution [1 was stirred into Solution I.

c. Preparation of filaments This spinning solution, having a viscosity of 3,250 poises at 20 C. (1 =2.05 as measured on a 0.5 percent by weight solution in N-methyl pyrrolidone at 20 C.) was spun through a l0-bore spinneret (diameter 0.1 mm.) into a precipitation bath (bath temperature 20 C.) comprising 70 parts by weight of water and 30 parts by weight of dimethyl acetamide. The filaments were run oil from the spinneret at a rate of meters per minute, subsequently washed in water at C. and finally pre-stretched at a ratio of 1:1.5 in boiling water. After drying. the filaments were stretched at a ratio of 1:1.5 at 350 to 380 C. over a cm. long heating frame. Highly heat-stable filaments having a tensile strength of 3.9 to 4.3 g./dtex at 5 percent elongation are obtained.

d. Dyeing of the filaments Ten g. fiber batches of this polyamide and of the un= modified homopolycondensate of 3-(p-aminophenyU-7- amino-r lH,3H)-quinazolin-2,4-dione and isophthaloyi dichloride were dyed at 120 C. with a percent by weight olution of the red azo dye quaternized with dimethyl sulphate. The solution was adjusted to pH and heated for 1.5 hours at 120' C. After dyeing, the strands were after-treated at C. with a 0.2 percent by weight aqueous solution of sodium bisulfite.

In order precisely to determine the improvement in dveability, 500 mg. batches of the treated fibers were dissolved in 25 cc. of dimethyl acetamide and the extinction values at 475 m compared with pure dimethyl acetamide were measured in a photometer (BFK. a product of Messrs. Kipp & Zonen). "Hie extinction values were E= L7 for the disulphi'mide-modified polyamide and E=0.l5 for the unmodified homopolycondensate.

EXAMPLE 2 a. Preparation of the disulphimide compound Two hundred parts by weight of a 20 percent by weight sodium hydroxide solution were added to a suspension of 236.5 parts by weight of 4-chloro 3-nitrobenzene sulphonamide in 1000 parts by weight of water. A solution of 142 parts by weight of 4-chloro-3-nitrobenzene sulphochloride in 300 parts by weight of acetone and 210 parts by weight of a 20 percent by weight sodium hydroxide solution were then simultaneously added dropwise at room temperature at such a rate as to maintain a pH value of from 11 to 12. After stirring for 2 hours at 50 C.. the reaction mixture was cooled, sodium di-(4-chloro-3-nitrophenyl)-disulphi' micle (mp 311 to 313 C.) was filtered oil under suction and washed with sodium hydroxide. Sodium'sdiM- chloro-J-aminophenyl)-disulphimide melting at 298 to 300 C. was smoothly obtained from this dinitro com pound by catalytic hydrogenation.

b. Preparation of the polyamide spinning solution Solution I: 134 Parts by weight of J-(p-aminophenyl J-7= amino( lH.3H)-quinazolin-2,4-dione were introduced into 970 parts by weight of absolute dimethyl acetamide. 101.5 Parts by weight of isophthaloyl dichloride were then introduced in portions with continuous stirring at 10 to 15 C.. and the resulting clear highly viscous solution was stirred for 16 hours at room temperature.

Solution II: In the meantime. a solution of a copoiycon densate was similarly prepared from 10.7 parts by weight of 3-(p-aminophenyl)-7-amino-(ll-I,3H)-quinazolin-2.4 dione, l6.7 parts by weight of sodium di-(3-amino-4 chlorophenyl)-disulphimide and 16.2 parts by weight of isophthaloyl dichloride in 131 parts by weight of absolute N-methyl pyrrolidone. Solution II was stirred into Solu= tion I.

c. Preparation of filaments This spinning solution, having a viscosity of 2,510 poises at 20 C. (i =l.9 as measured on a 0.5 percent by weight solution in N-methyl pyrrolidone at 20 C.) was spun through a l0-bore spinneret into an aqueous precipitation bath to form filaments. The filaments were run or? at a rate of 10 meters per minute. After stretching for 2 hours in boiling water and then on a frame heated at 260 to 280 C. to a final stretching ratio of 1:2.3, filaments with a tensile strength of from 4.0 to 4.5 g./dtex were obtained.

d. Dyeing of the filaments Comparative dyeing was also carried out with these polyamide filaments in the manner described in Example l d). The solution of the filaments, dyed with the same dye as in Example 1(d) in dimethyl aeetamide had an of tinction of E=2.4 (as against E=0.l5 for the solution oi the unmodified homopolymer).

EXAMPLE 3 a. Preparation of the disulphimi'de compound Three hundred parts by weight of a 20 percent by weight sodium hydroxide solution were added to a suspension of 303 parts by weight of 3-nitrobenzene sulphonamide in 1,600 parts by weight of water. A solution of 384 parts by weight of 4-chloro-3-nitrobenzene sulphochloride in 500 parts by weight of acetone and 300 parts by weight or a 20 percent by weight sodium hydroxide solution were then umultaneously added dropwise at room temperature at such a rate as to maintain a pH value of from 10 to ll. After stirring for 1 to 2 hours at about 50 C., the reactlOIl mixture was cooled. filtered under suction and washed with sodium hydroxide and water. The residue was 4- chloro-i-mtrophenyl-J-nitrophenyl disulphimide (melting point 246' to 247' C.) from which 4-chloro-3-aminophenvl- Y-aminophenyl disulphimide was smoothly obtamed by catalytic hydrogenation.

h. Preparation of the polyamide spinning solution Solution I. 155 Parts by weight of 1.3-bis-t p-arninophenylj-5,5-dimethyl hydantoin were dissolved in 800 parts by weight of absolute dimethyl acetamide. and 101.5 parts by weight of isophthaloyl chloride were gradually itlded with stirring at S to 10 C. The solution was stirred or 16 hours at room temperature and then mixed with Solution II. which was obtained by polycondensing 12.4 parts by weight of 1,3-bis-(p-aminophenyl)-S,5-dimethyl hyda; ein.an' aminophenyl-f-aminophenyl disulphimide with 16.2 parts by we ght of isophthaloyl chloride in 132 parts by weight of absolute dimethyl acetamide.

c. Preparation of the filaments This viscous spinning solution (n=l,8$ poises. =l.65. as measured on a 0.5 percent by weight solution of the polyamide in N-methyl pyrrolidone) was wet spun through a llLbore spinneret (bore diameter 0.1 mm.). The filaments were run off at a rate of to meters per minute. Water at 20' C. was used as the precipitation bath. After washing. the filaments were stretched in boiling water at a ratio of 1:1.5, dried and then stretched at a ratio of 1:1.5 at 330' to 350 C. on a stretching frame. Filaments of outstanding thermal stability with a tensile strength of 3.8 to 4.2 g./dtex at 7 percent elongation were obtained.

d. Dyeing of the filaments Comparative dyeing was carried out by the method described in Example 1(d). As described in Example ll d), the extinction of a solution of the filaments dyed with the same dye as in Example 1(d) was measured, as was 15:22 (compared with E=0.l8 for the solution of the unmodified homopolycondensate of l.3-bis-(p-aminophenvll-5,$-dimethyl hydantoin and isophthaloyl dichloride),

What we claim is:

l. A polyamide composition of matter that can be dyed with basic dyestuffs comprising a conventional high molecular weight aromatic fiber forming polyamide, containing repeating carbonamide groups as an integral part of the polymeric chain separated by a member selected from the group consisting of aromatic and aromatic heterocyclic moieties and from 3 to 30 percent by weight, based on the composition as a whole of a polyamide which comprises from 30 to 100 mol. percent of disultoneimide segments of the formula:

wherein each symbol A represents a group of the formula CONH or --NHC0,

: parts by weight of sodium-4-chloro-3- Z represents a hydrogen or alkali metal atom,

R represents a C to C. alkyl radical or an aromatic.

alkyl-substituted aromatic or halogen-substituted aromatic radical.

Ar and Ar, which can be the same or different, each represents a bivalent aromatic, alkyl-substituted aromatic or halogendisubstituted aromatic radical,

Ar represents a trivalent aromatic. alltylsubstituted aromatic or halogen-substituted aromatic radical. and

Y represents a divalent aromatic radical and from 0 to mol percent of said conventional aromatic polyamide segments.

2. The polyamide composition of claim 1, wherein said 3 to 30 percent by weight of a polyamide comprises Ar represents a radical of the formula:

(limit and A. R. Y and Z have the meaning as given in claim 1.

and from 0 70 mol percent of conventional aromatic polyamide segments.

3. A method for producing a polyamide composition of matter according to Claim 1 [J] which comprises adding. to a conventional aromatic polyamide. from 3 to 30 percent by weight of a polyamide [according to claim 3.). to a conventional aromatic polyamide.] comprising 30 I0 mol percent of disulfoneimide segments of the formula:

wherein each symbol .4 represents a group of the formula CONH or NHCO-.

Z represents a hydrogen or alkali metal atom.

R represents a C, to C alkyl radical or an aromatic. alkyl-subrtt'tuted aromatic or halogensrubstt'tuted aromatic radical.

13 Ar and Ar, which can be the same or difierent, each represents a bivalent aromatic, alkyl-substiruted aromatic or halogen-substituted aromatic radical, Ar represents a trivalent aromatic, alkyl-rubsziluted aromam'ce or halogen-substituted aromatic radical, and 1" represent: a divalent aromatic radical and from 0 to 70 mol percent of conventional aromatic polyamide segments.

References Cited The following references, cited by the Examiner, are of record in the patented file of this patent or the original patent.

UNITED STATES PATENTS 3,403,200 9/1968 Randall 260857 3,404,119 10/1968 Harper 260-857 3,477,899 11/1969 Kubitzek 260-857 3.514.498 5/1970 Okazaki 260-857 3,519,699 7/1970 Piezrusm 260-857 FOREIGN PATENTS 1,439,411 4/1966 France 260-857 PAUL LIEBERMAN, Primary Examiner US. Cl. X.R. 

